A disk drive is an information storage device. The most basic parts of a disk drive are at least one information storage disk that is rotated, an actuator that moves a slider carrying one or more transducers to various locations over the disk, and electrical circuitry that is used to write and read data to and from the disk. The one or more information storage disks are clamped to a rotating spindle. More specifically, storing data includes writing information representing the data to portions of tracks on a disk. The transducer includes two separate devices—a write transducer that writes information representing data to the disk and a read transducer or sensor that reads information from the disk.
Storing data includes writing information representing the data to the disk. Conventional disk drives with magnetic media organize data in concentric tracks. There is a constant goal in these storage devices to store increased amounts of data. Two ways of increasing the storage capacity of these storage devices include increasing the bit density, which means reducing the spacing between individual bits along the circumference of a concentric track or a substantially concentric track. The tracks can also be written as spirals in some applications. The bit density can be increased along the spiral path.
Another way to increase the capacity is to increase the track density. This involves writing the tracks more closely together.
Of course different writing techniques can be used to produce drives with more capacity. In the past, magnetic transitions were written longitudinally. Most recently, capacity increases have been achieved by writing the magnetic transitions perpendicular to the major surface of the disk. Different types of perpendicular magnetic recording have been developed. In the past, disk drives use a single type of perpendicular recording. The capacity of these disk drives is determined at the time of manufacture and generally remains static or fixed. Capacities of the disk drives do not increase. Sometimes the data capacities of the disk drives decrease.